KDP self-publishing
KDP Formatting Requirements: A Complete Checklist for Print and Ebook
The complete technical requirements for formatting a book for Amazon KDP, covering ebook file specs, print trim sizes, margins, bleeds, cover dimensions, and common rejection reasons.
Amazon KDP's formatting requirements are well documented, but scattered across multiple help pages. This checklist pulls the key technical requirements for both ebook and print formats into one place, so you can verify your files before uploading rather than after a rejection.
Formatting issues are one of the most common reasons a book upload fails review or looks wrong in KDP's previewer. Working through this checklist before uploading saves time and avoids re-uploads that can delay your publish date.
Ebook (Kindle) formatting requirements
Accepted file types
KDP accepts the following file types for Kindle ebooks:
| File type | Notes |
|---|---|
| EPUB | Recommended; accepted by KDP for most books and every other retailer |
| DOCX | Acceptable for simple manuscripts; KDP converts to Kindle format during upload |
| Accepted but not recommended for ebooks; reflowability is lost | |
| HTML (zipped) | Accepted but rarely used |
| MOBI | Still accepted but largely superseded by EPUB for most purposes |
For best results across Kindle devices and the Kindle app on phones, tablets, and browsers, a properly structured EPUB is the preferred format. A standard EPUB from a formatting tool also lets you use the same file on other retail platforms.
EPUB structure requirements
- A valid table of contents as a navigation document (NCX or NAV-based TOC)
- Cover image embedded within the EPUB and listed in the manifest
- Chapters accessible from the TOC (readers expect chapter navigation on Kindle)
- No password protection or DRM already applied to the file
- No unsupported media types embedded in the file that can't render on Kindle devices
Text and formatting requirements
- Fonts: standard web-safe fonts (Georgia, Times New Roman, Arial, etc.) or properly embedded fonts. KDP strips embedded fonts in some cases unless marked as subset-embedded correctly.
- Images: JPEG or PNG, embedded within the EPUB. Resolution of 300 DPI or higher is recommended; images will be downsampled if significantly larger.
- Special characters: use Unicode encoding throughout. Special characters should be encoded as UTF-8 characters, not as images.
- No headers or footers: ebooks reflow based on reader settings; fixed headers/footers (like those in a Word document) don't carry over meaningfully.
- Justified text: standard on Kindle, though KDP's rendering engine handles this automatically.
Cover image (ebook)
| Specification | Requirement |
|---|---|
| Dimensions | 2,560 x 1,600 pixels recommended (1.6:1 ratio) |
| Minimum dimensions | 1,000 pixels on the shortest side |
| Maximum dimensions | 10,000 pixels on either side |
| File format | JPEG or TIFF |
| Maximum file size | 50 MB |
| Color mode | RGB (not CMYK) |
The cover image for an ebook is a single flat image (front cover only, no spine or back). A higher-resolution image performs better on retina displays. The ebook cover is separate from the print cover.
Print (paperback) formatting requirements
Print formatting has more variables than ebook formatting because the specifications depend on your chosen trim size and page count.
Trim sizes
KDP Print supports a range of trim sizes. The most commonly used for fiction and nonfiction:
| Trim size (inches) | Common use |
|---|---|
| 5 x 8 | Fiction, poetry, standard-length novels |
| 5.06 x 7.81 | Mass market paperback style |
| 5.5 x 8.5 | Many nonfiction books |
| 6 x 9 | Nonfiction, self-help, textbooks, longer fiction |
| 8.5 x 11 | Workbooks, journals, technical manuals |
Choose your trim size before formatting. Your manuscript PDF must be exactly sized to the chosen trim size; images, margins, and page numbers must all be positioned relative to that size.
Margins
Margins ensure text doesn't fall into the spine or get cut off during printing. Minimum requirements vary by page count:
Gutter (inside margin): the gutter is the inner margin that accommodates the spine binding. KDP requires a minimum gutter based on page count:
| Page count | Minimum gutter |
|---|---|
| 24 to 150 pages | 0.375 inches |
| 151 to 300 pages | 0.5 inches |
| 301 to 500 pages | 0.625 inches |
| 501 to 700 pages | 0.75 inches |
| 701 to 828 pages | 0.875 inches |
Outside, top, and bottom margins: KDP recommends a minimum of 0.25 inches on all outside edges, though many books use 0.5 inches or more for a cleaner look. Text and images that extend to within 0.125 inches of the edge risk being trimmed.
Bleed
"Bleed" refers to content that intentionally extends to the edge of the page, useful for full-page images or colored backgrounds that should reach the paper edge. If you're using bleed:
- Extend bleed elements 0.125 inches beyond the trim line on all affected sides
- Set your PDF to "include bleed marks" or add 0.125 inches to the trim dimensions when exporting
- KDP accepts bleed content but requires that you confirm your PDF includes bleed when uploading
Most text-only books don't use bleed.
Interior PDF specifications
| Specification | Requirement |
|---|---|
| File format | PDF (version 1.3 or higher) |
| Fonts | All fonts must be embedded in the PDF |
| Color mode | Grayscale or CMYK for black-and-white books; CMYK for color books |
| Image resolution | 300 DPI minimum; 600 DPI recommended for sharp text in image elements |
| Page size | Exactly matches your chosen trim size (or trim + bleed where applicable) |
| Single pages (not spreads) | Each page is its own page in the PDF, not arranged as reader spreads |
| Page count limits | Between 24 and 828 pages for most trim sizes |
Black and white vs. color interiors
| Option | Use | Cost per page for printing |
|---|---|---|
| Black and white, white paper | Standard nonfiction, most fiction | Lowest |
| Black and white, cream paper | Fiction, especially longer literary works | Slightly higher |
| Standard color | Books with full-color images, cookbooks, children's picture books | Significantly higher |
| Premium color | Professional-quality color reproduction | Highest |
Color printing significantly increases the per-copy printing cost, which reduces the royalty available at a given retail price. Most authors of text-only books choose black and white.
Cover (print) specifications
The print cover is a single flat PDF that includes the front cover, spine, and back cover. Because the spine width depends on your page count and paper type, cover design needs to happen after your page count is finalized.
Spine width calculation
KDP provides a spine width calculator: enter your page count and paper type, and it returns the spine width in inches. General approximate values:
| Paper type | Approximate spine width per 100 pages |
|---|---|
| White paper (60# text) | 0.225 inches per 100 pages |
| Cream paper (60# text) | Similar to white, may vary slightly |
For a 300-page book on white paper: 3 x 0.225 = approximately 0.675 inches of spine width.
Cover image specifications
| Specification | Requirement |
|---|---|
| File format | |
| Color mode | CMYK |
| Resolution | 300 DPI minimum across the full cover |
| Total width | Front cover + spine + back cover, all measured in your trim size dimensions |
| Bleed | Extend all outer edges 0.125 inches beyond the trim line |
| Safe zone | Keep text and important images at least 0.125 inches inside the trim line on all edges |
Pre-upload checklist
Before uploading your files to KDP, check the following:
Ebook checklist
- EPUB validates without errors (use EPUBCheck or your formatting tool's built-in validation)
- Table of contents is present and links to every chapter
- Cover image is included at 2,560 x 1,600 pixels (or close to that ratio)
- All fonts used are web-safe or properly embedded
- No headers or footers that won't translate to ebook format
- Book opens to the correct starting page (front matter doesn't prevent readers from reaching chapter 1)
Print checklist
- Interior PDF page size exactly matches your chosen trim size
- All fonts are embedded in the PDF (not just referenced)
- Gutter (inside margin) meets the minimum for your page count
- Page numbers are on the correct pages (not on the cover page, blank pages, or part pages)
- Running headers, if present, are consistent throughout
- No text or images within 0.25 inches of the outer edges on any page
- Cover PDF is in CMYK, includes a 0.125-inch bleed, and spine width matches your page count and paper type
- KDP's print previewer shows no red-flagged pages
Hardcover formatting on KDP
KDP offers hardcover publishing as well as paperback. Interior formatting requirements for hardcovers are broadly similar to paperbacks, with the same trim size support and PDF specifications, but hardcover has different minimum page counts and printing cost structures that affect the minimum viable retail price.
The key practical note for formatting: the same interior PDF you produce for your paperback can typically be used for a hardcover edition as well, since the interior specifications are the same for a given trim size. The hardcover cover, however, requires a separate file sized to KDP's hardcover cover specifications, which differ from the paperback cover in spine width and overall dimensions.
Common issues caught by KDP's automated review
KDP's automated file-checking system reviews both interior and cover files on upload. Common flags and their fixes:
| Issue | Common cause | Fix |
|---|---|---|
| Page dimensions don't match trim size | Interior PDF exported at a different size than the chosen trim | Re-export from your formatting tool at the exact trim size |
| Fonts not embedded | PDF exported without font embedding enabled | Re-export with "embed all fonts" enabled |
| Cover spine width mismatch | Page count changed after the cover was designed | Recalculate spine width and update the cover file |
| Content outside safe zone | Text or images too close to the trim edge | Move content at least 0.25 inches from outer edges |
| Transparent cover elements | Transparency in cover PDF not flattened | Flatten transparency before exporting to PDF |
| Low resolution images | Images below 300 DPI in the interior | Replace with higher-resolution versions or scale images down |
| Missing NCX/NAV table of contents | EPUB doesn't include a navigable TOC | Regenerate EPUB using a tool that builds the TOC automatically |
How formatting tools help
Manually producing a KDP-compliant PDF in Word or Google Docs is possible but error-prone. The most common issues, incorrect gutter sizes, text too close to the trim edge, embedded-font failures, and incorrect page dimensions, are largely prevented by using a dedicated book formatting tool.
LiberScript's design mode shows a live, paginated preview at your chosen trim size with running headers and page numbers, so you can check the layout visually before exporting. It sets margins and gutter to safe defaults, and its print PDF export includes embedded fonts. Our full guide on how to self-publish on Amazon KDP covers the publishing process once your files are ready.
Frequently asked questions
What happens if my file doesn't meet KDP's requirements?
KDP reviews your files after upload, usually within a few hours. If the interior or cover fails a technical check, KDP will email you a rejection notice describing the issue. Common rejections include incorrect page dimensions, fonts not embedded in the PDF, and cover spine width that doesn't match the uploaded interior's page count.
Do I need to format separately for Kindle ebooks and print?
Yes. Kindle ebooks use a reflowable format (EPUB or DOCX) where readers control font size, while print books require a fixed-size PDF sized to your chosen trim size. Many formatting tools, including LiberScript, produce both from the same project.
Can I use a Word document for print?
KDP's upload system will accept DOCX for print books, but the conversion quality varies significantly. For a reliable result with correct margins, embedded fonts, and consistent chapter formatting, a print-ready PDF from a dedicated formatting tool is strongly preferred.
How do I know what spine width to use for my cover?
Use KDP's spine-width calculator, available in the cover upload section of the book setup process. You'll need your final page count and your chosen paper type. Your cover designer (or design tool) uses this measurement to position the front cover, spine text, and back cover correctly.
Should I design the cover before or after formatting the interior?
After. Your cover's spine width depends on your final page count, which is determined by your interior's trim size, font size, line spacing, and chapter structure. Even a minor change to the interior can shift the page count by enough to require a spine adjustment. Finalizing and approving your interior PDF, noting the final page count, and then building or ordering your cover prevents this.
Is it better to embed fonts or use system-standard fonts for print PDFs?
Embedding fonts is strongly preferred and required by KDP. System fonts that aren't embedded can reflow or be substituted during PDF rendering, resulting in unexpected appearance differences. Any formatting tool that exports print PDFs should embed fonts by default; verify this in your PDF export settings if you're using general-purpose software like Word or Adobe Acrobat.
The bottom line
Meeting KDP's formatting requirements consistently is a matter of following the technical specifications for your chosen trim size and paper type, checking your files in KDP's previewer before publishing, and fixing any flagged issues before you approve for publication. A dedicated formatting tool handles most of the technical constraints automatically, leaving you focused on the content and design of the book rather than margin arithmetic.
LiberScript's live preview at your chosen trim size lets you spot layout issues, margin problems, and running header inconsistencies before exporting. Its print PDF and EPUB exports are built to meet KDP's technical requirements by default, including embedded fonts and correctly sized pages, so you're checking for content and design quality rather than specification compliance.
See our complete KDP publishing guide for the full process from account setup to a live book on Amazon.
Ready to format your manuscript to KDP's specifications? Get started in LiberScript or see pricing for all plans.
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